What is Rolling Wave Planning?

Rolling Wave planning is a planning technique that involves elaborating more detail in your schedule as more information is available, or as you get nearer to the execution of the work. The idea is to plan in waves and clarify assumptions and approach as the execution of that a piece of work gets nearer.

At the onset of a project, we won’t know everything about late work at a detailed level, but we will have a general idea of about the work. Not only that, everything on a construction project may change quickly.

The concept of progressive elaboration applies to rolling wave planning, as you will continuously refine, add detail and clear up assumptions to constantly evolve your project schedule.

Often times, a project using rolling wave will clearly outline a planning schedule for elaborating a plan.

For example, the team might agree on 7 months prior to work execution, to have a level 5 detailed plan in place. The schedule will contain a level 3 or level 4 detail leading up to that point.

Of course, sometimes you are not going to know the details of a piece of work. In that case, you can use place holder activities at level 3 or level 4 in Primavera P6 to capture and hold a space for the work.

Here’s a example of that in Primavera P6:

Lastly, you’ll see above that AACE recommends that Rolling Wave Planning be used only on “longterm complex ventures”. I’ve seen this replaced elsewhere with the term “programs” or a very large multi-year undertakings.

This wording is meant to discourage the use and abuse of Rolling Wave on typical construction or oil & gas projects.

To try to get some further insight on using Rolling Wave, I asked around the www.aacei.org forums for opinions and guidance from other practioners.

The responses varied from “use with caution” to “you have what you need to build a detailed schedule if you look hard enough” to “use in the right context”. All of this is sound advice.

Now I think Rolling Wave can solve an important problem if used properly, and in the right situation as well. So please take these points into consideration as you explore this technique.

Rolling Wave Planning in Primavera P6

I’m going to show you the steps to elaborate level 3 or 4 activities with a series of detailed activities in Primavera P6. This process can be used for Rolling Wave Planning in Primavera P6 projects.

If you’d rather watch a video of how to implement my Rolling Wave Planning in Primavera P6 approach, scroll down to the video below.

The setup for Rolling Wave Planning in Primavera P6

First off, let me explain that in my example you’ll see the following setup:

1. My project has a Baseline

This is important to note and a key part of this technique relies on not removing activities from the project that are in the baseline. We keep all activities in the current project. We also add more detailed activities.

That way we can continue to compare our place holder activities to their counterparts in the baseline.

Make sense?

2. Place holder Activities can be on the critical path.

This isn’t a problem either. I will show you that we can add the detailed activities to the critical path, replacing the place holder activity.

3. WBS level remains the same.

One of the pitfalls of P6 is that you cannot convert an Activity into a WBS element. In this process of progressive elaboration, being able to take a long-duration Activity and converting it into a WBS element would be really handy.

But we don’t have that feature.

So I’m leaving my activities within the same WBS level in this rolling wave planning technique.

The place holder activity in Primavera P6 will become a summary Level of Effort Activity and additional detailed Activities will be added at the same level.

To do that, I need to put in place the links for a Level of Effort that tell it what to summarize.

I’ll assign it 2 new successors:

1 Fabricate Stands – Start-to-Start

6 Test Wheel Shop Equipment – Finish-to-Finish

Step 4 – Convert Your Placeholder to a Level of Effort

The last step is to change the Activity Type on Fabricate Wheel Shop Equipment to a Level of Effort. Then reschedule the project in P6.

Here’s the result of our Rolling Wave planning technique in Primavera P6.

Note that the project’s Critical Path now no longer includes the placeholder Activity as it did originally. The Critical Path now passes through the detailed Activities, as it should.

Also have a look at our new summary activity.

Did you notice that the total duration changed to 247 days?

That’s because Fabricate Wheel Shop Equipment now summarizes the activities below it and their total Duration is 247 days taking Calendars into account.

It will also expand if the work goes lates or contract if the work finishes early.

And we can continue to compare to the original baseline dates.

Watch the Video of Rolling Wave Planning in Primavera P6

Conclusion

You can use the Rolling Wave planning in Primavera P6 technique above to help you progressively elaborate a project schedule, either as you get more detailed information about the work or as you get nearer to the execution of the work.

Again, I think the best part of this approach is that your project continues to be in comparison with the baseline.

I’m always open to your feedback and comments. Let me know what you think.

About Michael Lepage

Michael is an avid project controls blogger and is the Chief Learning Officer here at Plan Academy. Michael has taught 1000s professionals how to use project controls software like Primavera P6 over the past 10 years through his online courses and tutorials. Michael is a member of AACE, the Guild of Project Controls and holds his PMP certification from PMI.

Michael,
Succint as always. I have used the technique to elaborate on the detail whilst keeping the continuity with previous programmes. The technique uses activity ID subscripts as part of an inteligent ID strategy to assist filters, searches etc. However the main point is the method of linking into the schedule. I have previously insisted to collegues that the correct relationship is to have the LoE activity as a successor to the 1st and last detailed task. i.e it only has predecessors (SS or FS and FF or SF) as appropriate to the nature of the linked activities. Also previous predecessors should be transferred to the relevant detail task and sucessors should link from the relevant detailed task. This makes a lot of work with icreased risk that the logic is not preserved. I notice you make no reference to the existing logic when the status is changed from activity to LoE.
Regards,
Nigel